A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Solve: sqrt(x^2 - 3x - 6) - 3 = x - 2

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    There is no solution to this. If it were \[\pm \sqrt{x ^{2} - 3x - 6} = x + 1\] Then the solution to the negative part would be (-7/5)

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Why do you say, that there's no solution? U just added 3 to both sides, so your equation isn't really any different from MargueriteSperduto's.

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    wait so whats the answer?

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    His answer is right, it's just wrong, that he says that there's no solution. \[\sqrt{x^2-3x-6} -3 = x-2\] If you're adding 3 to both sides you get this: \[\sqrt{x^2 -3x-6} = x+1\] Now you're squaring both sides: \[x^2-3x-6=(x+1)^2 \] This also equals: \[x^2-3x-6=x^2+2x+1\] Now you subscrat x^2 on both sides: \[-3x -6 = 2x+1\] Adding 3x on both sides gets you this: \[-6 = 5x+1\] Now you're subscrating one on both sides:\[-7=5x\] Et voila: \[x= \frac{-7}{5}\]

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    From an algebraic sense, you are correct there is a solution. However, in your steps to finding that answer, you had to square both sides which changes elements of the domain because of the square root. If you had checked your answer, you would indeed see that: \[\sqrt{x^2 -3x - 6} = x+1\] when \[x = (-7/5)\], gives you, \[(-2/5) = (2/5)\], hence why there is no real solution and the +- is necessary

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    And if you still don't believe me, let our genius friend explain: http://bit.ly/gJaIjy

  7. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.